The idle stop & go (ISG) system is equipped to reduce the fuel consumption and the emission of carbon dioxide. The ISG control means that the engine is automatically stopped after a vehicle is stopped (in the idle state) during running, and the engine can automatically be started without ignition when it is sensed that the driver is ready to drive.
In said vehicle ignition device which can implement ISG control, as shown in FIG. 1, the engine control unit (ECU) senses the ON/OFF state of the LPG switch (LPG SW) operated by the driver and drives the fuel pump motor according to the sensed ON/OFF state of the LPG SW of the engine to automatically start the engine.
Here, when the transistor (TR) used to start the driver in the ECU sensing the ON/OFF state of said LPG SW is shut off, said ECU is unable to sense the ON/OFF state of said LPG SW of said engine and thus continues to maintain the stop state of the engine.
Thus, to restart the engine, the starting motor (not shown in the drawings) of the ignition device keeps on running. This reduces the durability of the starting motor.
In addition, when said LPG SW is in the OFF state, the ECU is unable to diagnose the EFR relay which supplies power to the fuel pump motor.